The subject of the present invention is a device for precipitating foreign matter from a gas stream, with at least one crossflow precipitator unit which has an inlet duct bounded by a baffle element and a rotationally symmetrical, concave impingement surface which is disposed coaxially to this inlet duct and is curved at a distance around the mouth of the inlet duct, so that an annular outlet duct is formed between the impingement surface and the back of the baffle element.
In known devices of this generic type (German Specification Nos. 2,641,765 C3 and 2,659,647 A1), the baffle and impingement surfaces of channel-type profile parts are formed in such a way that each baffle surface overlaps adjacent longitudinal edges of two impingement surfaces, and vice versa. The profile parts can also be of hollow design, to allow a heating or cooling medium to flow through, and can thus form a heat exchanger which can be connected to a heat recuperator. Nozzles through which a cleaning fluid can be sprayed can also be arranged on the baffle and impingement surfaces.
European Specification No. AZ 0,004,720 describes a precipitator which is used especially for internal combustion engines and in which the air stream which is to be purified passes without significant deflection through a wall assembled from several precipitator elements. By means of appropriately formed spin surfaces, the gas stream is set into rotation in each precipitator element, the entrained dust being concentrated in the peripheral edge zone by centrifugal force and then being tangentially discharged through an orifice. Perfect functioning of this precipitator is entirely dependent on the individual rotating gas streams not interferring with one another. For this reason is is indispensible, even if the gas streams of mutually adjacent precipitator elements rotate in opposite directions, to screen the individual precipitator elements rheologically from one another by partitions; this requires additional expense and, moreover, reduces the overall efficiency of the unit.
It is therfore the object of the invention to propose a device of the type initially set out, which permits uncomplicated assembly of an entire precipitator wall from a multiplicity of precipitator elements, without separation of the precipitator elements from one another being necessary; moreover, an improvement in the efficiency of the known units and preferably also in their noise behavior is intended.